Breaker point assembly for internal combustion engines



Jan. 3, 1956 A. c. RUSSELL 2,729,

BREAKER POINT ASSEMBLY FOR INTERNAL COMBUSTION ENGINES Filed Sept. 13.1954 United States Patent BREAKER POINT ASSEMBLY FOR INTERNAL COMBUSTIONENGINES Andrew C. Russell, Shawnee, Okla. Application September 13,1954, Serial No. 455,483 3 Claims. (Cl. 200-166) This invention relatesto the field of internal combustion engines and, more particularly, toimprovements in breaker point assemblies for use in the distributormechanisms forming a part of such engines.

It is the principal object of this invention to provide a breaker pointassembly of improved construction which gives a more positive making andbreaking action upon the electrical circuit controlled and which permitsthe passage of greater amounts of electrical current through theassembly during periods when the circuit is made than has heretoforebeen possible with practicable, prior devices used for the same generalpurpose. Experimental tests have conclusively demonstrated that the useof the improved breaker point assemblies of this invention not onlyincrease the power available from an internal combustion engine, butalso increase the running time or mileage which may be had from a givenamount of fuel.

Obviously, one of the larger fields of application for this invention isin connection with the distributor mechanisms of automobiles and othermotor vehicles, although it is to be understood that the usefulness ofthe invention extends to any internal combustion engine utilizing adistributor mechanism having a rotatable cam for operating a breakerpoint assembly.

Another of the very important objects of this invention is to provide abreaker point assembly which results in substantial economies inmanufacture by virtue of the fact that the working parts of the assemblyhave been simplified and a substantial portion of same may be formed inone operation as a unitary body of plastic material or the like.

Other important objects of the invention, including certain importantdetails of construction rendering the assembly uniquely wear-resistant,simplifying replacement of parts when same does become necessary andachieving other advantages which will become clear, will be fullyexplained or become apparent as the following description of theinvention progresses.

In the accompanying drawing:

Figure l is a fragmentary view of a distributor mechanism of an internalcombustion engine showing the cam forming a part of such mechanism andthe assembly of this invention in elevation;

Fig. 2 is a cross-sectional view taken centrally through the main blockportion of the assembly on line II-II of Fig. 4;

Fig. 3 is a sectional view taken centrally of the block portion of theassembly at right angles to the section of Fig. 2 on line III-III of thelatter;

Fig. 4 is a top plan view of the assembly taken on line IV-IV of Fig. 1;

Fig. 5 is a fragmentary view of the body of the assembly in its initialcondition after manufacture and before the cam-follower portion thereofhas been bent into its operative position; and

Fig. 6 is a fragmentary, top plan view of a modified form of theassembly of this invention.

The problem of increasing the current flow through 2,729,725 Ce PatentedJan. 3, 1956 the electrical ignition circuits of an internal combustionengine during periods of make of the breaker point assemblies used inthe distributor of the engine, has long challenged the manufacturers ofautomobiles and other internal combustion engine devices. Difficulty hasalways been experienced with prior types of breaker point assemblies, inthat, the current which could be conducted by same during the makeportion of the cycle was limited or the structure provided with a viewto increasing such current was impractical and not conducive to positivemaking and breaking action. Moreover, attempts to improve upon theconventional types of breaker point assembly in common use, have been socomplicated as to be either impractical in operation or prohibitive fromthe standpoint of manufacturing cost.

It is these problems and difficulties which the present inventionovercomes by providing a breaker point assembly of increased simplicityand operational efficiency.

Referring first to Fig. l, the numeral 10 generally designates adistributor mechanism of an internal combustion engine. Mechanism 10conventionally includes a base 12 and a rotatable cam 14.

The breaker point assembly of this invention is broadly designated bythe numeral 16 and includes a body generally designated 22 and contactstructure broadly designated 24.

Body 22 is preferably formed of a strong, wear-resistant, insulatingplastic material, such as nylon or the like, and includes a main,block-like portion 26, a mounting portion 28, and an extension portion30. Portions 26, 28 and 30 are preferably integral with each other sothat the body 22 is of unitary nature and may be formed by a singlemanufacturing operation such as is well known in the art of plasticsfabrication.

The main body portion 26 is substantially rectilinear in configurationand is provided with a straight, elongated bore 32 passing therethrough,bore 32 having a portion of its length of reduced diameter as at 34.Mounting portion 28 extends from the main body portion 26 as mostclearly illustrated in Fig. 1 and is provided with a number ofperforations 36, 38 and 40 adapted to coincide with the usual fasteningmeans 42, 44 and 46 which are conventionally provided upon the base 12of distributor 10 for the mounting of a breaker point assemblytherewithin. It may be noted that perforations 36 and 38 are preferablyelongated to permit adjustment of the position of assembly 20 relativeto the cam 14 through swinging of mounting portion 28 about the pivotprovided by fastening means 46.

As best indicated in Fig. 5, the extension portion 30 of body 22 mayinitially extend essentially straight out- Wardly from one face 48 ofmain body portion 26. However, extension portion 30 includes a sectionof decreased thickness as at 50, so that extension portion 30 may bebent to the position illustrated in Fig. 1 disposing a projection 52 ofportion 30 for engagement with cam 14 and an opposed surface 54 ofportion 30 in partially covering, spaced relationship to the end of bore32 adjacent face 48 of main body portion 26. Due to the decreasedthickness of section 50 of extension portion 30 and the fact that thebody 22 is formed of slightly flexible material, it will be clear thatextension portion 30 may swing toward and away from face 48 of bodyportion 26 as projection 52 rides upon cam 14.

Electrical contact structure 24 includes a stationary plate 56 ofelectrically conducting material rigidly mounted upon a face 58 of bodyportion 26 opposite to face 48 of the latter by any suitable fasteningmeans 60, such as screws threaded into main body portion 26. Secured toplate 56 are a plurality, in the illustrated embodiment a pair, ofcontacts 62 and 64 which are preferably rigidly secured to plate 56 inspaced relation to one another by any suitable means such as arivet-like flange 66. Contacts 62 and 64 are preferably of highlyconductive material and may be of copper, silver or the like. Suchcontacts 62 and'6'4 are, except for the portions 66 thereof provided forriveting or fastening to plate 6, substantially cylindrical inconfiguration and are each provided with a flat end face 68. Electricalconnection to contacts 62 and 64 is accomplished by conductive means 70coupled with plate 56 in any suitable manner as by soldering to a lug 72engaged and held by one of the fastening screws 60.

Electrical contact structure 24 also includes an elongated rod 74reciprocably mounted within bore 32 of main body portion 26 andextending from the latter at each end thereof. Rod 74 is preferably ofenlarged diameter as at 76 adjacent the end thereof proximate face 54 ofextension portion 30. Enlarged portion 76 of rod 74 is slidable withinthe main part of bore 32, while the remainder of rod 74 is slidablyjournaled in the reduced diameter portion 34 of bore 32, it being notedthat plate 56 is provided with an opening 78 adapted to clear rod 74without electrical contacting engagement with the latter. An elongatedelement 80 is secured in any suitable fashion upon the opposite end ofrod '74 and rigidly carries a plurality of contacts corresponding to thecontacts 62, 64, etc., in the illustrated embodiment a pair of contacts82 and 84 respectively opposite contacts 62 and 64. Contacts 82 and 84may be secured to element 80 as by a rivet flange 86 or in any othersuitable manner. Contacts 82 and 84, like contacts 62 and 64, arepreferably formed of highly conductive material and are each providedwith a fiat face88 of substantial area directly opposed to the flat face68 of the corresponding contact 62 or 64.

A strong compression spring 90 is disposed within bore 32 and around thesmaller diameter portion of rod 74. The ends of spring 90 respectivelybear against the enlarged portion 76 of rod 74 and a shoulder 92presented adjacent the zone 34 of decreased diameter-of bore 32. It willbe clear, therefore, that spring '90 yieldably biases rod 74 in adirection to move contacts 82 and 84 into engagement with contacts 62and 64 respectively and to move enlarged portions 76 of rod 74 intoengagement with face 54 of extension portion 30 of body 22.

Main body portion 26 is provided with a straight, elongated, lateralpassage 94 communicating with bore 32 adjacent face 48 of the portion 26and extending therefrom toward the surface 96 of body 22 which bearsagainst base 12 of distributor when the assembly 20 is mounted as shownin Fig. 1. Within passage 94, as shown in Fig. 3, there isprovided anelongated contacting member 98 which is reciprocable toward and awayfrom enlarged portion 76 of rod 74, the latter being provided with avertical groove 100 adapted to receive the end of contactingelement 98.Element 98 is biased toward rod portion'76 by a compression spring 102,which at its opposite end, bears against a screw plug 104 threaded intomain body portion 26.

Screw plug 104 also carries a star washer 106 adapted to engage and makeelectrical contact with base 12 of distributor 10 when the assembly 20is in place. It is to V be understood that base 12 will normally'be ofconductive metallic material constituting the grounded side of thesystem, so that electrical connection with contacts 82 and 84 ismadethrough base 12, start washer 106, metallic screw plug 104, metallicspring 102, metallic contact element 98, the enlarged portion 76 ofmetallic rod 74, and the metallic supporting element 80 which carriescontacts 82 and 84. The riding of contact element 958 7 within .groove10 0. of rod portion 76 therefore accomplishes two purposes, first, by.Virtue of the biasing effected by spring 102 and the electrical pathjust mentioned, it serves to ground rod 74 and thereby contacts 82 nd 84f he ass mbly .0, and ec n y, it p e en s rotation of rod 74 and therebyserves to maintain con? tacts 32 and 84 in alignment with stationarycontacts 62 and 64.

An alternate form of construction is illustrated in Fig. 6 wherein isprovided a bore 132 that is polygonal in cross-section rather than roundas was the case with bore 32 of the first described embodiment of theinvention. In this modified form, the rod 74 is provided with anenlarged portion 176 which is of polygonal cross-section correspondingwith that of the polygonal bore 132. Such construction serves tomaintain alignment between the contacts 82 and 84 and the contacts 62and 64 by preventing rotation of the rod 74, without the utilization ofa groove 100 having an element 93 riding therein. It will be understoodhowever, that an element 98 will be provided as above described forbearing against the rod portion 176 to establish electrical groundingcontact therewith.

it will now be apparent that simple, practical, structure has beenprovided in combination by'this invention by which all of theabove-mentioned objects and advantages may be fully enjoyed. It willalso be obvious that certain minor modifications or changes could bemade from the exact details illustrated and described without departingfrom the true spirit and intention of the invention.

Accordingly, it is to be understood that the invention 7 shall be deemedlimited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. As an article of manufacture, a blank for use in a breaker pointassembly, said blank comprising a unitary body of insulating materialhaving a main, block-like portion provided with a bore therethrough, anda cam follower extension portion integrally attached to said mainportion and provided with a zone of reduced dimension adjacent theextremity thereof attached to said main portion, said extension portionbeing bendable at said zone thereof and of dimensions for disposition ofa part thereof remote from its said extremity in spaced alignment withone extremity of said bore, whereby said extension portion is adapted toextend between an external cam and one extremity of a contact-carryingelement forming a part of said assembly and shiftably mountable in saidbore, to be oppositely engaged by said cam and said element, and toswing about said zone thereof toward and away from said extremity of thebore for shifting the element responsive to the cam. V a

2. As an article of manufacture, a blank for use in a breaker pointassembly, said blank comprising a unitary body of plastic, insulatingmaterial having a main, substantially rectilinear, block-like portionprovided with a straight, elongated bore therethrough, and an elongatedcam follower portion initially extending from said main portion in onedirection and having a zone of reduced thickness at which it may be bentto dispose the longitudinal axis of said cam follower portion in adifferent direction with a part of the latter adjacent its free endspaced from said main portion and in alignment with said bore.

3. In an article as set forth in claim 2, wherein said body includes amounting portion integral with said main portion and extendingtherefrom, said mounting portion being provided with perforationsadapting thesame for securement to the base of a conventionaldistributor mechanism.

References Cited in the file of this patent UNITED STATES PATENTSChermendy Feb. 1, 1938

